No, don't need to remove the door decor trim strips to renew the outer seals.
You can gently prise the strips off the studs, either the clip will pull free of the stud or more likely the strip will come off the clip, they only bump on. But be careful as easy to damage a strip if you bend it too much and then they stay with a kink in it.
Shoot up a pic of the hood trim if you have one. Is is the right length for the hood width? Camaro used a slightly different profile but also a different length and can't be used on Firebird hoods. If you mean the strong, raised centre line shape then no, the hood strips seem to taper off from each end to a more plain, slightly curved strip across the centre with the centre line much softer. I'd imagine if the length is correct then you have the right piece.